COMPARATIVE GENOMIC HYBRIDIZATION ANALYSIS OF WILMS-TUMORS

In this study we have applied the technique of comparative genomic hyb ridization (CGH) to a large series of sporadic Wilms tumors, including six samples of the associated nephroblastomatosis. The data obtained were compared with the findings of molecular studies carried out on th e same mate rial. The aims of the study were (1) to characterize the r ange of genetic variation in sporadic Wilms tumor and nephroblastomato sis, (2) to determine whether changes could be found that have not bee n detected by commonly used techniques, and (3) to compare the sensiti vity of CGH with that of conventional molecular analysis. The chromoso mes that showed gains and losses by CGH were similar to those previous ly found in molecular and cytogenetic studies, however loss of 4q was a new event identified in 2 out of 46 tumors. We did not detect amplif ied genetic material. Comparison of the data from the nephroblastomato sis and tumor samples from the same patient showed that loss of 7p may be associated with malignant transformation, and that losses in 1p, 1 1p, 4q and gains in 1q and 12q can be early events; whilst loss in 9p and gain of 8, 10q and 18 are possible secondary changes in tumor deve lopment. The combined CGH and molecular techniques used demonstrated i nvolvement of two specific 1p regions in the etiology of Wilms tumor.